The present invention relates to a lawn mower blade for rotary lawn mowers and, in particular, to a novel mulching blade for rotary lawn mowers of the type used by commercial lawn services and commercial landscapers.
In performing lawn services and landscaping service in the nature of mowing lawns and trimming, it is a consistent desire to mulch the grass clippings as fine as possible so that the clippings can be utilized as nutrients, beneficial to the lawn, by having the clippings gravitationally filtered down to the soil. At the outset, rotary-type lawn mowers had poor distribution of grass clippings which required additional labor to rake the clippings for disposal and thereby deprive the lawn of the nutrient value of the clippings. There have been improvements in the mower blades utilized with rotary mulching mowers in an attempt to minimize this problem and the collection of clipping deposits within the rotary blade housing which have deleterious effects upon mower performance. In particular, Wininger in U.S. Pat. No. 3,003,298; Davis in U.S. Pat. No. 2,836,024; Cope in U.S. Pat. No. 3,538,692 and Freedlander in U.S. Pat. No. 3,343,352 have addressed attempted improvements in mulching the lawn clippings utilizing either a particularly shaped blade or a combination of blade and housing improvements to improve the mulching characteristics of the particular mower.
Applicant's invention is directed towards a novel blade for obtaining improved mulching characteristics. Applicant's rotary blade could have application to lawn mowers of the domestic type in which a single rotary blade revolves within a housing, but Applicant's invention is more particularly suited to commercial or industrial rotary mowers in which there are usually two or three rotary blades positioned within sectionalized housings and powered by a single engine utilizing either pulley or gear connections for the rotation of the blades.
Applicant's novel blade structure is designed to induce and control the turbulence within the blade housing to ensure that the grass clippings are subjected to a plurality of significant contacts with the cutting edge of the blade.